CN110493864A - A kind of quasi-synchronous CDMA method under the synchronous condition based on clock steering - Google Patents
A kind of quasi-synchronous CDMA method under the synchronous condition based on clock steering Download PDFInfo
- Publication number
- CN110493864A CN110493864A CN201910696823.5A CN201910696823A CN110493864A CN 110493864 A CN110493864 A CN 110493864A CN 201910696823 A CN201910696823 A CN 201910696823A CN 110493864 A CN110493864 A CN 110493864A
- Authority
- CN
- China
- Prior art keywords
- signal
- clock
- synchronous
- steering
- cdma
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
- H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
- H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
- H04B7/0613—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission
- H04B7/0678—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission using different spreading codes between antennas
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/14—Relay systems
- H04B7/15—Active relay systems
- H04B7/185—Space-based or airborne stations; Stations for satellite systems
- H04B7/1851—Systems using a satellite or space-based relay
- H04B7/18519—Operations control, administration or maintenance
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W56/00—Synchronisation arrangements
- H04W56/001—Synchronization between nodes
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W72/00—Local resource management
- H04W72/04—Wireless resource allocation
- H04W72/044—Wireless resource allocation based on the type of the allocated resource
- H04W72/0446—Resources in time domain, e.g. slots or frames
Abstract
A kind of quasi-synchronous CDMA method under the synchronous condition based on clock steering is disclosed, it can be such that CDMA runs under the conditions of quasi synchronous, suitable for there are the opening wireless channels of relay node, in satellite communication system, it is also applied for the opening wireless channel there is no relay node.Quasi-synchronous CDMA method under this synchronous condition based on clock steering, under open wireless channel, multiple dispatching stations share power resource using CDMA spread spectrum transmission mode and send signal；Use external guidance signal, it is synchronous that clock is provided for CDMA signal transmitted by multiple terminal stations in open wireless channel, and multiple terminal stations are eliminated to relay node or the path delay of time difference of receiving station, so that realizing the plesiochronous reception of multichannel signal in the received multichannel signal clock synchronization of relay node or institute, receiving station, phase alignment.
Description
Technical field
The present invention relates to the standard under the technical field of wireless communication more particularly to a kind of synchronous condition based on clock steering is same
Walk code division multiplex access method.
Background technique
CDMA (Code Division Multiple Access, CDMA) access way distributes not different user
Same spectrum-spreading address code realizes that satellite resource is shared, and identical frequency is occupied between CDMA user while being sent, and leads between user
The orthogonality of numeral is crossed to distinguish user, (Frequency Division Multiple Access, frequency division are more compared to FDMA
Location), CDMA technology is relative complex, is chiefly used in starlike networking.
CDMA technology is used by the second generation (IS-95) and the third generation (CDMA2000) communication standard, becomes mainstream
One of communication system.Meanwhile CDMA technology sends the features such as signal power is low, also widely answers because of its anti-interference, good confidentiality
In military communication.CDMA technology is compared to FDMA and TDMA technology, the advantage with soft channel capacity.Using FDMA and
The communication system of TDMA (Time Division Multiple Access, time division multiple acess), when number of users more than frequency band number and when
When gap number, system is just unable to satisfy the communication needs of other users, therefore TDMA and FDMA technology has hard channel capacity limit.
And CDMA technology can use Multiuser Detection, improve user capacity.
In satellite communication return link, CDMA multiple access multiplexing technology has been widely adopted.Firstly, the transmission of CDMA technology
Power is all lower compared to TDMA and FDMA, therefore has good confidentiality；Secondly, as previously mentioned, CDMA is compared to FDMA
There is the advantage of soft channel capacity with TDMA, by effective multiuser detection, the communication that can satisfy more users is needed
It asks；Again, CDMA technology can fight narrowband interference；Finally, CDMA technology can reduce the EIRP value of back transmission, avoid pair
The interference of adjacent star especially meets the communicating requirement of " communication in moving " satellite communication system.Therefore, either wireless communication system or
Satellite communication system, CDMA technology are all with a wide range of applications.
In DS-CDMA (Direct Sequence-Code Division Multiple Access, direct sequence code point
Multiple access) in, the symbol of each user is modulated by one group of orthogonal waveforms.Each user be assigned to one it is orthogonal with other users
Waveform.Fig. 1 is the system model of DS-CDMA technology.In principle, DS-CDMA is believed by that will carry the narrowband of information
The wideband spread-spectrum signal for number being multiplied and obtaining with high speed address code signal.Receiving end needs the identical address code synchronous with originator
Signal goes the carrier phase of control input converter that despreading can be realized.DS-CDMA system has the interference of anti-narrowband, anti-multipath
The advantages of decline and good confidentiality.Remaining advantage of DS-CDMA: many users can share frequency resource, without complicated frequency
Distribution and management；With " soft capacity " characteristic, i.e., number of users within certain limits increases, and only can signal-to-noise ratio be declined, and
Communication will not be terminated, that is to say, that DS-CDMA not absolute capacity limit.
But traditional CDMA is directly applied in geo-synchronous orbit satellite communication and is existed due to needing stringent synchronization
Very big difficulty.
The period of geo-synchronous orbit satellite operation is equal to the track of earth rotation period.If the eccentricity of this track
It is all zero with inclination angle, i.e. the sub-satellite track position of the satellite remains constant, and satellite is all from the point of view of any point from the earth
Be it is static, this track is referred to as stationary orbit.For the Geo-synchronous circular orbit that inclination angle is not zero, sub-satellite track is
The highest dimension of one " 8 word " shape, the north and south latitude that satellite is leapt is equal to its orbit inclination angle.If satellite transit is by perturbation shadow
It rings, " 8 word " shape of distortion will be presented in ground sub-satellite track.This results in the elevation angle that earth station needs real-time tracing satellite, and
And overcome the problems, such as that thus bring synchronizes inaccurate.
Summary of the invention
To overcome the shortcomings of existing technologies, the technical problem to be solved in the present invention is to provide a kind of same based on clock steering
Quasi-synchronous CDMA method under the conditions of step, can be such that CDMA runs under the conditions of quasi synchronous, to be suitable for existing
The opening wireless channel of relay node is also applied for the opening wireless channel there is no relay node in satellite communication system.
The technical scheme is that the quasi-synchronous CDMA method under this synchronous condition based on clock steering,
Under open wireless channel, multiple dispatching stations share power resource using CDMA spread spectrum transmission mode and send signal；
Using external guidance signal, it is same that clock is provided for CDMA signal transmitted by multiple terminal stations in open wireless channel
Step, and multiple terminal stations are eliminated to relay node or the path delay of time difference of receiving station, so that in relay node or institute, receiving station
Received multichannel signal clock synchronization, phase alignment, realize the plesiochronous reception of multichannel signal.
The present invention under open wireless channel, share power resource using CDMA spread spectrum transmission mode and send by multiple dispatching stations
Signal；Using external guidance signal, clock is provided for CDMA signal transmitted by multiple terminal stations in open wireless channel and is synchronized,
And multiple terminal stations are eliminated to relay node or the path delay of time difference of receiving station, so that being received in relay node or receiving station
Multichannel signal clock is synchronous, phase alignment, realize the plesiochronous reception of multichannel signal, therefore CDMA can be made to exist
It is run under the conditions of quasi synchronous, thus suitable for there are the opening wireless channels of relay node also to fit in satellite communication system
For the opening wireless channel of relay node to be not present.
Detailed description of the invention
Fig. 1 shows the system model of DS-CDMA technology.
Fig. 2 shows the schematic diagrames of nonstatic geo-synchronous orbit satellite sub-satellite track.
Fig. 3 shows the flow chart for obtaining steering signal.
Fig. 4 shows the schematic diagram of pilot frame structure according to a preferred embodiment of the present invention.
Specific embodiment
Quasi-synchronous CDMA method under this synchronous condition based on clock steering,
Under open wireless channel, multiple dispatching stations share power resource using CDMA spread spectrum transmission mode and send signal；
Using external guidance signal, it is same that clock is provided for CDMA signal transmitted by multiple terminal stations in open wireless channel
Step, and multiple terminal stations are eliminated to relay node or the path delay of time difference of receiving station, so that in relay node or institute, receiving station
Received multichannel signal clock synchronization, phase alignment, realize the plesiochronous reception of multichannel signal, that is, QS-CDMA
(Quasi-Synchronized Code Division Multiple Access)。
The present invention under open wireless channel, share power resource using CDMA spread spectrum transmission mode and send by multiple dispatching stations
Signal；Using external guidance signal, clock is provided for CDMA signal transmitted by multiple terminal stations in open wireless channel and is synchronized,
And multiple terminal stations are eliminated to relay node or the path delay of time difference of receiving station, so that being received in relay node or receiving station
Multichannel signal clock is synchronous, phase alignment, realize the plesiochronous reception of multichannel signal, therefore CDMA can be made to exist
It is run under the conditions of quasi synchronous, thus suitable for geo-synchronous orbit satellite communication.
Preferably, external guidance signal includes clock synchronization information, the lasting benchmark timing information of steady and continuous, is received
Multiple terminal stations that the external guidance signal comes in guarantee system realize that clock is plesiochronous on the basis of external clock, and establish
Time reference.
Further, if there are relay nodes in open wireless channel, and in relay node position or motion profile
Under the conditions of known, the internal loopback of detection frame is realized in each terminal station by relay node, measures the terminal station and relaying saves
Point absolute distance, send CDMA signal multiple terminal stations to respectively relative to the range difference of relay node make phase mend
It repays, so that transmitted multichannel signal realizes phase alignment when reaching relay node, in conjunction with based on external guidance signal
Clock it is plesiochronous, realize clock and phase alignment based on external guidance signal, guarantee multichannel signal in relay node
Plesiochronous combining and and then station of breaking in the reception realize plesiochronous reception.
Alternatively, if non-relay node, multiple terminal stations send CDMA letter to the same terminal station in open wireless channel
Number when, based on external guidance signal realize clock it is quasi synchronous on the basis of, multiple sending terminal stations respectively to receive terminal station
Test frame is sent, and receives the test response of terminal station response, a pacing of going forward side by side determines each sending terminal station and receives terminal station
The distance between；Is made to the range difference respectively relative to reception terminal station by phase benefit for the multiple terminal stations for sending CDMA signal
It repays, so that transmitted multichannel signal realizes phase alignment when reaching and receiving terminal station, believes in conjunction with based on external guidance
Number clock it is plesiochronous, realize that clock based on external guidance signal is synchronous and phase alignment, guarantee that multichannel signal is connecing
Receive the plesiochronous reception in terminal station.
Be preferably based on external guidance signal realize clock it is plesiochronous after, by accomplished continuously or intermittently receive external guidance letter
Number keep clock synchronous, and sending terminal station to relay node or receives the distance change in terminal station and accumulates at any time, sends whole
End station periodically sends detection frame to relay node or reception terminal station, redeterminates distance, resetting phase, realizes phase pair
Together.The performance of quasi-synchronous CDMA is decided by that the phase alignment precision synchronous with clock, the precision corresponded in ranging cycle time
Sending terminal station and relay node or the variation for receiving relative position between terminal station.
Further, to guarantee plesiochronous received performance in CDMA, the phase alignment precision is less than spread-spectrum code chip
The 1/4 of width.
Further, GPS and dipper system are for supporting the plesiochronous received external guidance signal source of CDMA, GPS/
The geographical location information that dipper system provides accurately clock synchronization for terminal station and is capable of providing each terminal station, if in channel not
There are relay nodes, then direct measuring goes out the distance between multiple CDMA signalling terminals station and reception terminal station and sending
It holds difference of adjusting the distance to make compensation, realizes the plesiochronous reception for receiving terminal station to multichannel signal；If there is relaying in channel
Node then after the position of acquiring relay node or trace information, measures the distance between sending terminal station and relay node, more
Range difference between the transmitting terminal pair and relay node of road CDMA makes compensation, realizes that the standard of multichannel signal at relay node is same
Step combining, and it is further implemented in the plesiochronous reception of the multichannel signal of receiving end.The effect of CDMA signal phase alignment
The steady accuracy of clock and positioning accuracy depending on GPS/ Beidou signal.
Further, as shown in figure 3, the reference clock is obtained by steering signal；The steering signal are as follows:
A terminal station is selected in open wireless channel as benchmark, sends steering signal all the way, steering signal occupies
The whole frequency bands or partial-band of open wireless channel are sent, whole frequency bands that steering signal occupies in open wireless channel or
Partial-band is guiding frequency band, and the proportional region that pilot power accounts for guiding frequency band whole power is 0.1 ‰ -5%, guiding letter
Number send when spread by spreading code, with the low-power spectrum signal mode of noise like be superimposed upon guiding frequency band in communication believe
On number, the influence of receiving end background thermal noise is lower than to the influence of receiving end signal received signal to noise ratio；
Steering signal is that the terminal station of polymorphic type in channel constructs network and is in communication with each other that provide guiding, carrier wave and clock same
Step, standard timing and instruction information.
Further, as shown in figure 4, the steering signal includes: frame head, frame number and instruction information data body.Frame
Head includes synchronous head, pilot tone, and synchronous head is used for steering signal frame timing and carrier auxiliary, and pilot field is for eliminating steering signal
The frequency deviation of frame；Frame number field is the mark to steering signal frame circular order；Indicate information data body field carrying instruction letter
Breath, is used to indicate channel, network state and management information；Each terminal station carries out demodulation reception to the steering signal, extracts load
Wave, clock information, the mark frame number through the period of fixed signal frame and in signal frame obtain clock reference, according to leading
Instruction information in fuse number identifies the base station for sending guidance information and completes the reception of other instruction information.
Preferably, locking range is in 1/2~1/32 time slot.Wherein 1/32 time slot effect is best, and CDMA can be made to approach
It is run under synchronous regime.
Specifically, the signal that dispatching station is sent, the length of each frame are fixed, and the information rate of each frame is fixed, therefore every
Time span representated by one frame is also fixed, therefore the receiving station sends the interval between the signal frame of signal by dispatching station
Time interval is determined, by basic unit of the interval as clock between signal frame；Pass through the time between different serial number frames
Difference carrys out deadline calibration, if two frame time gap count of front and back is not equal to the signal frame period, receiving station's clock is adjusted
It is whole.
Grounded receiving station continuously receives steering signal, and can be to each frame received in steering signal according to frame structure
It distinguishes, as steering signal, the length of each frame is fixed, and the information rate of each frame is fixed, therefore representated by each frame
Time also fix, therefore grounded receiving station can determine time interval by the interval between steering signal frame, by signal
Basic unit of the interval (that is, signal frame period) as clock between frame, by the time difference between different serial number frames come complete
At time calibrating, if two frame time gap count of front and back is not equal to the steering signal frame period, grounded receiving station clock needs
It is adjusted.
Further, the periodic regime of signal frame is in 50ms~250ms.When the signal frame period be 50ms, 100ms,
It is best as the basic unit of clock and the effect of calibration when the integral multiple of these 50ms of 150ms, 200ms, 250ms.
When steering signal transmitting terminal is satellite, steering signal are as follows:
It is superimposed a steering signal on each data signal carrier of satellite and passes through satellite broadcasting；The guiding letter
Number by spreading code carry out spread spectrum communication, and power be communication satellite coverage power 1 ‰ -1%；
In a network, the steering signal of user receiving station listening satellite completes user receiving station by receiving steering signal
It is synchronous with the clock of satellite clock.
When signal sending end is the administrative center station in earth station, steering signal are as follows:
On each data signal carrier of the earth station as signal sending end, it is superimposed a steering signal；
In the earth station as signal receiving end, demodulation reception is carried out to the steering signal, extracts the information of carrier wave,
To be identified to the earth station as signal sending end；
The steering signal carries out spread spectrum communication by spreading code, and power is the 0.1 ‰-of communication satellite coverage power
5%.
Specifically, the steering signal includes: frame head (Header), pilot tone (Pilot), frame number (ID) and data volume
(Data Frame).Fig. 4 shows the schematic diagram of pilot frame structure according to a preferred embodiment of the present invention.
Further, frame head is used for steering signal frame timing and carrier auxiliary, and length is in 16~128bit；Pilot field
For full 0 field, length is in 60bit or more, for eliminating the frequency deviation of steering signal frame；Frame number field length in 8bit or more,
For being measured to earth station absolute distance；Data volume field bearer network management information is used for and nets other interior station administrations
With maintenance satellite network information, length is in 256~1008bit.
Further, distinguishing channel and when spreading rate, using ovsf code (Orthogonal Variable Spreading Factor OVSF,
Orthogonal Variable Spreading Factor.Ovsf code is mainly used for orthogonal spectrum expansion.The rate of Traffic Channel is not
Together, the length of the ovsf code used is also different).It is that ovsf code has orthogonality using the reason of ovsf code, length can be changed again.
Further, frequency expansion sequence uses ovsf code.Thus support variable bit rate is brought.
Further, the steering signal uses binary phase shift keying BPSK mode circular modulating, continuously
It keeps sending；It is equipped with a steering signal receiver for each subscriber station, steering signal receiver solves steering signal
Expand, it is then directly hard to receive, the signal frame of steering signal is obtained, information bit is judged by frame head, continuously receives steering signal
It is plesiochronous to complete clock.Since GDP frame length and time are fixed, it is plesiochronous that clock can be completed in continuous reception GDP.
Wherein, for big signal (signal of more than half that can push away completely entire transponder power is attributed to big signal), lead to
The frame head of TDMA frame is crossed to rearrange, to complete to receive, is then eliminated big signal, obtaining small signal (can push away completely entire
The signal below of the 10% of transponder power is attributed to small signal) mixed signal, mutually orthogonal ovsf code is recycled, to small
Signal mixed signal is de-spread, to complete to receive.
Wherein, for middle signal (10%~50% signal that can push away completely entire transponder power is attributed to middle signal),
Due to the orthogonality of ovsf code, despreading can be directly completed using corresponding spreading code and is received, to obtain target letter
Number.
Preferably, the periodic regime of signal frame is in 50ms~250ms.
When the signal frame period is the integral multiple of these 50ms of 50ms, 100ms, 150ms, 200ms, 250ms, as clock
Basic unit and calibration effect it is best.
Preferably, by the phase difference of transmitting terminal and receiving end, the variation of absolute distance between satellite and earth station is obtained.
During administrative center station continuously transmits steering signal, satellite can constantly be moved around the earth, and phase
It is mobile that " 8 " word track is presented for substar, therefore satellite and administrative center the distance between stand and constantly to change, therefore lead
The path delay of time of fuse number can constantly change, but the certain regularity of mobile presentation of satellite, be all by as far as closely again by closely to
It far is changed, therefore certain regularity is also presented in the variation in the path delay of time.
It stands for administrative center, steering signal is received by itself, be sent to the link paths Delay Variation of satellite and connect
It is consistent to receive the link paths Delay Variation from satellite-signal, thus steering signal receiving end and steering signal transmitting terminal it
Between phase delay with being equivalent to double star the path delay of time change, therefore work as spread spectrum communication receiver, detect maximum phase
Guan Feng is mobile to some direction, can obtain phase delay while tracking maximum correlation peak, the half of phase delay is
The path delay of time, the path delay of time can be obtained the absolute distance between satellite and earth station multiplied by the light velocity and change.
Preferably, by between the ground satellite station of coarse-grain between absolute distance and the ground satellite station of fine granularity
Absolute distance variation, realizes satellite ranging.
By steering signal, it can use administrative center station and send the absolute time of specific frame number frame and receive specific
The absolute time of frame number frame is carried out making the difference the absolute path time delay that can be obtained between ground satellite station, is multiplied i.e. with the light velocity
The value of absolute distance star can be obtained, but because of the path delay of time of satellite communication in 280ms or so, absolute distance is at one section
Sampling is less in time, is unable to complete point-device satellite ranging.
But by the variation that absolute distance is added, this value is measured with the movement of band spread receiver maximum correlation peak
, whithin a period of time, number of samples is very big, therefore can carry out completion to absolute distance by the variation of absolute distance,
Between two absolute distances, the absolute distance of intermediate time point is predicted by the changing value of absolute distance, to complete height
The satellite ranging of precision.
Preferably, the steering signal uses binary phase shift keying BPSK mode circular modulating, continuously keeps
It sends.It can make all earth stations in network that can receive steering signal in this way.
The above is only presently preferred embodiments of the present invention, is not intended to limit the present invention in any form, it is all according to
According to technical spirit any simple modification, equivalent change and modification to the above embodiments of the invention, still belong to the present invention
The protection scope of technical solution.
Claims (9)
1. a kind of quasi-synchronous CDMA method under synchronous condition based on clock steering, it is characterised in that: in open wireless communication
Under road, multiple dispatching stations share power resource using CDMA spread spectrum transmission mode and send signal；
Using external guidance signal, clock is provided for CDMA signal transmitted by multiple terminal stations in open wireless channel and is synchronized,
And multiple terminal stations are eliminated to relay node or the path delay of time difference of receiving station, so that being received in relay node or receiving station
Multichannel signal clock is synchronous, phase alignment, realize the plesiochronous reception of multichannel signal.
2. the quasi-synchronous CDMA method under the synchronous condition according to claim 1 based on clock steering, feature exist
In: external guidance signal includes clock synchronization information, the lasting benchmark timing information of steady and continuous, receives the external guidance
Multiple terminal stations that signal comes in guarantee system realize that clock is plesiochronous on the basis of external clock, and settling time benchmark.
3. the quasi-synchronous CDMA method under the synchronous condition according to claim 2 based on clock steering, feature exist
In: it is each if there are relay nodes in open wireless channel, and under the conditions of known to the relay node position or motion profile
The internal loopback of detection frame is realized in terminal station by relay node, measures the absolute distance of each terminal station and relay node, is sent
Phase compensation is made to the range difference respectively relative to relay node in multiple terminal stations of CDMA signal, so that transmitted multichannel
CDMA signal realizes phase alignment when reaching relay node, plesiochronous in conjunction with the clock based on external guidance signal, realizes base
In the clock and phase alignment of external guidance signal, guarantee that multichannel signal exists in the plesiochronous combining of relay node and in turn
It receives terminal station and realizes plesiochronous reception.
4. the quasi-synchronous CDMA method under the synchronous condition according to claim 2 based on clock steering, feature exist
In: if non-relay node in open wireless channel is being based on when multiple terminal stations send CDMA signal to the same terminal station
On the basis of external guidance signal realizes that clock is quasi synchronous, multiple sending terminal stations respectively send test frame to reception terminal station,
The test response that terminal station is responded is received, the distance between each sending terminal station and reception terminal station are determined in a pacing of going forward side by side；Hair
Send multiple terminal stations of CDMA signal to respectively phase compensation is made relative to the range difference for receiving terminal station, so that transmitted
Multichannel signal realizes phase alignment when reaching and receiving terminal station, then the clock based on external guidance signal is plesiochronous, real
Now the clock based on external guidance signal is synchronous and phase alignment, guarantee multichannel signal connect in reception the plesiochronous of terminal station
It receives.
5. according to claim 1 based on the quasi-synchronous CDMA method under clock steering synchronous condition, feature described in -4
It is: after realizing that clock is plesiochronous based on external guidance signal, keeps clock by accomplished continuously or intermittently receiving external guidance signal
Synchronous, and the distance change of sending terminal station to relay node or reception terminal station is accumulated at any time, sending terminal station is to relaying
Node or reception terminal station periodically send detection frame, redeterminate distance, resetting phase, realize phase alignment.
6. the quasi-synchronous CDMA method under the synchronous condition according to claim 5 based on clock steering, feature exist
In: to guarantee that plesiochronous received performance in CDMA, the phase alignment precision are less than the 1/4 of spread-spectrum code chip width.
7. the quasi-synchronous CDMA method under the synchronous condition according to claim 6 based on clock steering, feature exist
It is for supporting the plesiochronous received external guidance signal source of CDMA in: GPS and dipper system, GPS/ dipper system is terminal station
The geographical location information that accurately clock synchronization is provided and is capable of providing each terminal station, if relay node is not present in channel,
Direct measuring goes out multiple CDMA signalling terminals station and receives the distance between terminal station and make in transmitting terminal difference of adjusting the distance
The plesiochronous reception for receiving terminal station to multichannel signal is realized in compensation；If there are relay nodes in channel, relaying is known
Behind the position of node or trace information, the distance between sending terminal station and relay node are measured, in the transmitting terminal of multichannel
Compensation made between the range difference relay node, realizes the plesiochronous combining of multichannel signal at relay node, goes forward side by side one
Step realizes the plesiochronous reception in the multichannel signal of receiving end.
8. the quasi-synchronous CDMA method under the synchronous condition according to claim 6 based on clock steering, feature exist
In: the reference clock is obtained by steering signal；The steering signal are as follows:
A terminal station is selected in open wireless channel as benchmark, sends steering signal all the way, steering signal, which occupies, to be opened
The whole frequency bands or partial-band of wireless channel are sent, the whole frequency bands or part that steering signal occupies in open wireless channel
Frequency band is guiding frequency band, and the proportional region that pilot power accounts for guiding frequency band whole power is 0.1 ‰ -5%, steering signal hair
It is spread when sending by spreading code, the signal of communication in guiding frequency band is superimposed upon with the low-power spectrum signal mode of noise like
On, the influence of receiving end background thermal noise is lower than to the influence of receiving end signal received signal to noise ratio；
Steering signal be polymorphic type in channel terminal station construct network and being in communication with each other provide guiding, carrier wave it is synchronous with clock,
Standard timing and instruction information.
9. the quasi-synchronous CDMA method under the synchronous condition according to claim 8 based on clock steering, feature exist
In: the steering signal includes: frame head, frame number and instruction information data body.Frame head includes synchronous head, pilot tone, and synchronous head is used
In steering signal frame timing and carrier auxiliary, pilot field is used to eliminate the frequency deviation of steering signal frame；Frame number field is to leading
Draw the mark of signal frame circular order；Indicate information data body field carrying instruction information, be used to indicate channel, network state and
Management information；Each terminal station carries out demodulation reception to the steering signal, extracts carrier wave, clock information, passes through fixed signal frame
Period and the mark frame number in signal frame, obtain clock reference, transmission is led according to the instruction information in steering signal
The base station of fuse breath is identified and completes the reception of other instruction information.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910696823.5A CN110493864B (en) | 2019-07-30 | 2019-07-30 | Quasi-synchronous code division multiple access method based on clock guide synchronization condition |
| PCT/CN2020/105101 WO2021018123A1 (en) | 2019-07-30 | 2020-07-28 | Quasi-synchronous code-division multiple access method based on clock guide synchronization condition |
| US17/630,931 US20220278744A1 (en) | 2019-07-30 | 2020-07-28 | Method for quasi-synchronous code division multiple access based on synchronization clock by piloting |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910696823.5A CN110493864B (en) | 2019-07-30 | 2019-07-30 | Quasi-synchronous code division multiple access method based on clock guide synchronization condition |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110493864A true CN110493864A (en) | 2019-11-22 |
| CN110493864B CN110493864B (en) | 2020-07-10 |
Family
ID=68548816
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910696823.5A Active CN110493864B (en) | 2019-07-30 | 2019-07-30 | Quasi-synchronous code division multiple access method based on clock guide synchronization condition |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US20220278744A1 (en) |
| CN (1) | CN110493864B (en) |
| WO (1) | WO2021018123A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111711509A (en) * | 2020-04-26 | 2020-09-25 | 四川润泽经伟信息技术有限公司 | Intelligent user interference system and method based on satellite communication countermeasure |
| WO2021018123A1 (en) * | 2019-07-30 | 2021-02-04 | 北京大学 | Quasi-synchronous code-division multiple access method based on clock guide synchronization condition |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110518957B (en) * | 2019-07-30 | 2020-11-06 | 北京大学 | Bypass network guiding method in open wireless channel |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1455992A (en) * | 2000-09-28 | 2003-11-12 | Ses阿斯特拉有限公司 | Spread spectrum communication system using quasi-geostationary satellite |
| EP1548963A2 (en) * | 2003-12-27 | 2005-06-29 | Electronics and Telecommunications Research Institute | Reference clock recovery apparatus and method |
| CN101355374A (en) * | 2007-07-24 | 2009-01-28 | 重庆无线绿洲通信技术有限公司 | Method for generating signal of non-interference quasi-synchronous CDMA communication system |
| US20100128757A1 (en) * | 2008-11-21 | 2010-05-27 | The Hong Kong University Of Science And Technology | Spreading sequences with dual low correlation windows for quasi-synchronous code-division multiple-access communications |
| CN104581926A (en) * | 2014-09-25 | 2015-04-29 | 上海欧科微航天科技有限公司 | Accurate uplink quasi-synchronization time measurement method for low-earth-orbit satellite communication |
| CN105554868A (en) * | 2015-12-04 | 2016-05-04 | 盐城工学院 | Ad-hoc network MAC quasi-synchronization protocol communication method on the basis of CDMA |
| CN109217968A (en) * | 2018-08-17 | 2019-01-15 | 盐城工学院 | A kind of near radio network using CDMA technology based on phase-shift keying (PSK) technology |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20120264371A1 (en) * | 2011-04-18 | 2012-10-18 | Electronics And Telecommunications Research Institute | Apparatus and method for controlling time synchronization between base stations |
| AU2013307021B2 (en) * | 2012-08-21 | 2015-11-05 | Mitsubishi Electric Corporation | Communication system, communication terminal, communication method, chip clock generation method, and orthogonal code generation method |
| CN104062895A (en) * | 2014-06-26 | 2014-09-24 | 桂林电子科技大学 | Pseudolite time synchronization method and positioning method thereof |
| CN104316938B (en) * | 2014-09-25 | 2016-10-19 | 上海欧科微航天科技有限公司 | A kind of New Satellite simulator for the plesiochronous communication system of low orbit satellite |
| KR20160100534A (en) * | 2015-02-16 | 2016-08-24 | 한국전자통신연구원 | Apparatus and method of generating network clock reference packet for acquiring network synchronization in a two-way satellite communication system |
| CN110493864B (en) * | 2019-07-30 | 2020-07-10 | 北京大学 | Quasi-synchronous code division multiple access method based on clock guide synchronization condition |
-
2019
- 2019-07-30 CN CN201910696823.5A patent/CN110493864B/en active Active
-
2020
- 2020-07-28 WO PCT/CN2020/105101 patent/WO2021018123A1/en active Application Filing
- 2020-07-28 US US17/630,931 patent/US20220278744A1/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1455992A (en) * | 2000-09-28 | 2003-11-12 | Ses阿斯特拉有限公司 | Spread spectrum communication system using quasi-geostationary satellite |
| EP1548963A2 (en) * | 2003-12-27 | 2005-06-29 | Electronics and Telecommunications Research Institute | Reference clock recovery apparatus and method |
| CN101355374A (en) * | 2007-07-24 | 2009-01-28 | 重庆无线绿洲通信技术有限公司 | Method for generating signal of non-interference quasi-synchronous CDMA communication system |
| US20100128757A1 (en) * | 2008-11-21 | 2010-05-27 | The Hong Kong University Of Science And Technology | Spreading sequences with dual low correlation windows for quasi-synchronous code-division multiple-access communications |
| CN104581926A (en) * | 2014-09-25 | 2015-04-29 | 上海欧科微航天科技有限公司 | Accurate uplink quasi-synchronization time measurement method for low-earth-orbit satellite communication |
| CN105554868A (en) * | 2015-12-04 | 2016-05-04 | 盐城工学院 | Ad-hoc network MAC quasi-synchronization protocol communication method on the basis of CDMA |
| CN109217968A (en) * | 2018-08-17 | 2019-01-15 | 盐城工学院 | A kind of near radio network using CDMA technology based on phase-shift keying (PSK) technology |
Non-Patent Citations (4)
| Title |
|---|
| 崔淼: "准同步码分多址系统序列设计及应用研究", 《中国优秀硕士论文电子期刊网》 * |
| 张璇: "准同步CDMA通信系统扩频序列设计", 《中国博士学位论文电子期刊网》 * |
| 李玉博: "准同步码分多址系统扩频序列设计理论研究", 《中国博士学位论文电子期刊网》 * |
| 段少华，张中兆，张乃通: "准同步CDMA及其在卫星移动通信中的应用", 《高技术通讯》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2021018123A1 (en) * | 2019-07-30 | 2021-02-04 | 北京大学 | Quasi-synchronous code-division multiple access method based on clock guide synchronization condition |
| CN111711509A (en) * | 2020-04-26 | 2020-09-25 | 四川润泽经伟信息技术有限公司 | Intelligent user interference system and method based on satellite communication countermeasure |
| CN111711509B (en) * | 2020-04-26 | 2023-04-28 | 四川润泽经伟信息技术有限公司 | Intelligent user interference system and method based on satellite communication countermeasure |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2021018123A1 (en) | 2021-02-04 |
| CN110493864B (en) | 2020-07-10 |
| US20220278744A1 (en) | 2022-09-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110493864A (en) | A kind of quasi-synchronous CDMA method under the synchronous condition based on clock steering | |
| KR100372494B1 (en) | Method and apparatus for mobile station location within a communication system | |
| AU681483B2 (en) | Method of transmitting and receiving power control messages in a CDMA cellular radio system | |
| CA2266951C (en) | Method and apparatus for adjacent service area handoff in communication systems | |
| ES2337637T3 (en) | TIMING SYNCORNIZATION ASSISTED BY MOBILE STATION IN A CDMA COMMUNICATION SYSTEM. | |
| CN1239387B (en) | Method of allocating optimum walsh codes to reverse link | |
| EP0865223A2 (en) | Mobile station position estimation for cellular mobile communication system | |
| KR20050120794A (en) | A method and apparatus for supporting p2p communication in tdd cdma communication systems | |
| KR20020020792A (en) | Method and apparatus for sequentially synchronized network | |
| JP2014112872A (en) | Method for supporting user positioning in intra-structure coverage system | |
| CN104506267B (en) | A kind of plesiochronous cut-in method of the uplink of multimedia LEO satellite communications and device | |
| WO2005088336A1 (en) | Method and system for determining position of terminal by using location detector in gps satellite-invisible area | |
| US11888512B2 (en) | Method for piloting from bypass in a network with open wireless channels | |
| CN1848708B (en) | Method of measuring receive power of CDMA mobile communication system, and CDMA mobile communication system | |
| WO2002011317A1 (en) | A tdd framing method for physical layer of a wireless system | |
| JP2000004212A (en) | Line estimating device and radio communication device | |
| US20220247482A1 (en) | Method for piloting from bypass in a network based on satellite load platform | |
| RU2787776C1 (en) | Method for quasi-synchronous multiple access with code separation based on clock frequency synchronization conditions | |
| EP1299960B1 (en) | A reverse synchronization method in a wireless system | |
| JP4086631B2 (en) | Radio base station apparatus and path search method | |
| RU2784459C1 (en) | Method for providing pilot signal from bypass channel in network with open wireless communication channels | |
| van Nee | Timing aspects of synchronous CDMA | |
| AU758090B2 (en) | Method and apparatus for adjacent service area handoff in communication systems | |
| JP2602246B2 (en) | Mobile satellite communication / positioning method | |
| AU743859B2 (en) | Method and apparatus for adjacent service area handoff in communication systems |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |